When should I charge my iPhone 4S?

I got an iPhone 4S today and my friend said don't charge it until it's at like, 5% and don't take it off the charger until its full because it messes up the battery. Is that true?

What your friend says isn't true, but if you want your battery to last all day, you know like while your out shopping or with your friends then the best thing to do is charge it every night while your in bed, that way its ready to go the next day if you need it.